The Tasmanian tiger is dead, extinct, no more. Even if it were to be resurrected by cloning, it would only survive in refuges. Reintroduce Tasmanian tigers into the wild and they could become extinct again because of lack of bush to feed in, wild dog attacks, or possibly infections like mange.
Eastern quolls only exist in Tasmania now, mostly in the high country populated by skiers, not farmers. Spotted quolls are deemed to be ‘vulnerable’ in some areas, ‘endangered’ in others – and extinct in many more. In the 1970s in my own area, I used to see fresh spotted quoll scats at least twice a week around our henhouse (netted on the top to stop the quolls climbing up and over to eat the chooks). Quoll chook raids were at least a monthly occurrence up at the village of Majors Creek. There have been only two quoll raids in a fifty-kilometre radius in the past decade. One of those quolls was caught in Majors Creek and taken tens of kilometres away last month, to save the chooks – or rather, to save the chooks whose owners have not provided them with a quoll-and feral cat-proof wire-covered run. That quoll will try to go ‘home’ and may well be shot or run over as it does so. I haven’t seen any fresh quoll scats in the past decade and have had only one sighting of another and her young last year – they were feeding on wombat roadkill by the side of the mountain track.
Quolls have been killed by farmers with shotguns or dogs, or trapped and poisoned. These are what killed the Tasmanian tiger, too. But quolls face an even worse threat: toxoplasmosis spread by feral cats.
It appears that there is considerable individual difference in reaction to toxoplasmosis. For now, far too little is known about it and the research that is being done is privately funded, not governmental. It may be that the animals most susceptible to behaviour modification will die, leaving a stronger residual population. It may also be possible that, like the Tasmanian tiger, our native predator animals may all become extinct.
Why does this matter, except to sentimentalists? (Of whom I’m one: I want these animals to survive because they are beautiful and because they add to the diversity not just of the ecology but of my life.)
The more simplified an ecosystem the more vulnerable it is. One grass species can die in a drought or a wet year. Forty ground cover species mean stability: if one dies out there are others to take its place. Yet other predators like foxes, feral cats and wild dogs have taken at least part of the quoll and tiger’s places in our ecology, cleaning up dead meat and taking the weakest of their target species so that the survivors breed strong young.
But not entirely. Feral cats feed mostly on birds and lizards. Foxes, in our area, eat roadkill carrion, and fruit like avocadoes, blackberries and apples (at times they are almost entirely vegetarian). When they do hunt in our area, it is mostly frogs. Wild dogs are large enough to haunt the edges of paddocks to take lambs, a lot more meat and easier hunting than rabbit or hare.
Quolls and Tasmanian tigers had different prey. Quolls in our area feed mostly on animals that are already dead, although they eagerly raid hen houses and, in our valley at least, also eat frogs. Tasmanian tigers probably scavenged much of their food from dead animals too. They were more scavenger than predator. But quolls – and probably Tasmanian tigers – also kill and eat sick, elderly and weak animals. It may seem illogical to encourage a predator which might eat other endangered animals, but to think this is to misunderstand the role of a predator, to fail to listen to the land. A certain degree of predation makes a species genetically stronger, so that the weak do not breed, and the fastest, fittest and most intelligent survive.
Quolls – and tigers – were part of the balance of the ecology where they once fed. This is even more clearly seen in the loss of predator birds.
7 Predator birds and plague cockatoos
Farmers believed eagles, goshawks and other predator birds ate lambs. They do – dead or dying ones.11 But they were shot and poisoned in their tens of thousands, and some still are despite their protected status. The birds were also forced to hunt in the open paddocks where they were vulnerable because their favourite prey – young possums, wonga pigeons, even frogs – had vanished with the forests.
These days cockatoos are seen as the most destructive of bird pests. They consume entire crops and will even destroy verandas and red cedar garden furniture. For sixteen years I tried to keep the sulphur-crested cockatoos off our walnut crop. I failed. Finally, I left the nuts to the cockatoos. About five years later they noticed the newly fruiting apple trees by our house. Disaster, I thought. Then I noticed one white cockatoo sitting slightly apart from the others. A hunchbacked cockatoo.
It wasn’t. It was a white goshawk. White goshawks eat sulphur-crested cockatoos, but only if they haven’t been shot or their eggs made fragile by DDT or other poisons, including surfactants from herbicide spraying or from eating prey that themselves have eaten poisoned bait.
If you watch a mob of white cockatoos feeding – the long drives near Canberra’s Parliament House are a good place to spy on cockatoos – you’ll see that they always have lookouts posted high in the trees while the others feed on grass seeds. Once, before white farmers and their guns and poisons, a mob of cockatoos would be followed by predators, like white goshawks, who have evolved to be able to sneak into a flock, grab one and be off.
That year the cockatoos moved off a few hours after the white goshawk arrived – slightly fewer cockatoos than there had been before.
Australian orchardists and crop farmers and back yard gardeners do not have a sulphur-crested cockatoo problem: they have a white goshawk deficiency – and a powerful owl, wedge-tailed eagle and little eagle deficiency too, and of the many other large birds that eat cockatoos. But any meat-eating bird is vulnerable, at the top of the food chain where pesticides and other toxins like heavy metals bioaccumulate. And as our waterways become more polluted, the predator birds dwindle in numbers.
By how much? Good question. It is a pity that the funding has been cut to the institutions that might be evaluating just that, and its implications.
8 The decline of snakes and lizards
How much have snake and lizard populations declined? Don’t know. What are the implications? Don’t know that either, and from extensive trawling through research papers for the past forty-five years, I strongly suspect that no one else knows or is even working on a viable way to find out. Australia has some of the deadliest snakes in the world and had an extraordinary diversity of lizards. They have had some significant role in the ecology, but what it was and its ramification will probably never be known.
I do, however, have one anecdote. Every autumn, for forty years, we have had a build-up of roof rats: not bush rats, which may run across the rafters of our shed and hop onto the benches, but the introduced brown rat, Rattus norvegicus. Sometimes we have rats nesting in our ceilings all year round, but not in the past twelve months. No scuffles, no squeaks, no arguments with the ringtail possum who lives above the dining room.
What is different this year? It’s been the third year in a row of reasonable rainfall, so there should have been more rats, not fewer. But early this spring I met a large, pure black python in our vegetable garden, asleep on the bed where we grow our early zucchini. It heard me, then sped off towards the house.
I don’t know what species of python it is – there are diamond pythons nearby so it may be a different-coloured variant. It may also be a species that has never been identified, and possibly won’t be before it becomes extinct. Black pythons have, however, been sighted as far away as Monga, thirty kilometres to our northeast, and twelve kilometres downstream in Araluen, though that specimen was dead and may have been washed down by floodwater. The snake is known locally as a ‘marsh snake’.
Pythons eat rats. Pythons also like ceiling spaces, especially above rooms heated in winter, so they have no need for such a long winter hibernation. This was a big, well-fed python. And perhaps, just perhaps, it has kept the rats under control over about four hectares.
Mice and bush rats breed up into plagues t
hat devastate wheat and other crops. Perhaps if we had left more snake and lizard habitat – boulders, rocks, swampy bits at the bottom of the paddock, shrubby undergrowth along streams – and not turned the land into one vast grassland (wheat, too, is a grass) we might have more reptiles and fewer, or far smaller, rat and mouse plagues.
9 Christmas beetle plagues
Plagues of Christmas beetles are almost certainly a postcolonial event. Like many pests, Christmas beetles recognise their food supply by its silhouette. The park-like paddocks created by the colonials – a few trees left in each – were perfect Christmas beetle territory, allowing them to pass from one food supply to another.
Every Christmas for sixteen years, the stringybark sapling outside our front gate would be totally defoliated by the beetles. The same species, roughly the same age and two metres away, was untouched and grew to a twenty-metre tree in that time, while the stringybark by the gate stayed stunted.
The difference? The one two metres away was in bush – real bush, with over forty species of shrubs and sub-shrubs around it. The other stood sentinel-like by itself. Eventually that sapling did grow into a tree, but only after the other bush species grew around it.
There were other factors, of course: one of those shrubs is a Bursaria spinosa, host for various parasites that eat Christmas beetle larvae. But mostly it was simply that the beetles could easily find the tree. Australia is not naturally like European parks or farms. Our trees grow with other species, in clusters by waterholes, along watercourses, in bush or in gullies. They don’t stand alone like specimen trees in your front garden. And, if they are made to do so, they’ll get eaten, or develop root rot (Phytophthora cinnamomi) from lack of microfauna to control it. (Phytophthora cinnamomi is inhibited by wattle bark and wattle slash mulch and, I suspect, by the decaying wattles of natural bushland too. Wattles are short lived and many species regularly shed their bark or a large numbers of seedpods.)
In Europe, sheep and cattle like sunlight, often a rare commodity. In Australia they seek shade, and the ground under mature gum trees is often their camp during the day, leading to soil compaction. No new seedlings emerge from the hard ground as the tree begins to shed copious viable seed before it dies or, if they do, they are eaten or sat on.
The European farm vision of men like Peter Ffrench could have been perfectly designed to create agricultural disaster.
10 Introducing weeds and helping them flourish
I am not going to attempt to find figures for the amount of pastureland lost to weeds; the cost of weed removal each year in Australia; the impact of herbicides on amphibian and other non-target species (I doubt if substantiated figures exist). Shall we just say that the answers to these questions would be ‘lots’.
But I will tell you about the broom and blackberry up in Majors Creek. Almost annually for forty years these weeds have been sprayed with herbicide. Each time they die back, and more seedlings grow in the bare ground and take their place. Each year the herbicide spreads a little further than the weeds – spraying tends to do that. Without the ground covers, broom seeds and blackberry runners take the place of grass. Forty years of spraying has led to roughly four times the area under broom and blackberry than there was forty years ago.
This is not a difficult pattern to see. But every few years, someone takes up the dream of controlling the weeds with a good spray, hoping that, by some miracle, the easy solution will work this year. The weeds will stay there until they are managed by someone who accepts that it isn’t enough just to kill the weeds. You need something to colonise and stabilise the soil where the weeds have been.12
Weeds colonise ground left bare by erosion and overstocking. Weeds are natural colonisers: they need disturbed ground to take over. (This can happen naturally, after storm and flood, but it’s rare. The bush here that has neither been grazed nor burnt in bushfire is pretty much weed free, despite the heavy weed burden metres away.)
Introduced farming and grazing techniques creates opportunities for weeds. They also introduced most of the weeds. Look at the declared weed list for your area: it is unlikely that there will be many – or even any – that are native to your area, though there may be a few native to another state or even a different area of your own state. (Native plants, like Cootamunda wattles and Pittosporum undulatum can become weeds outside their native territory.)
These weeds are a product of a vision of our land as ‘one nation’. Australia was once hundreds of nations and is still a land of thousands of eco-types. Yet a red flowering gum from Western Australia is regarded as a ‘native plant’ in New South Wales, comparable to calling Italian lavender native to Scotland. Cootamundra wattle is not a weed in Cootamundra, nor are pittosporums weeds here, but in places like the Dandenongs in Victoria they are invasive and to be avoided.
11 Pollution of waterways
Polluting of waterways with superphosphate and nitrogenous fertilisers leads to algal blooms, dead fish, sterile water systems, loss of frogs, illness in humans and plagues of mosquitoes, whose larvae would otherwise have been eaten by those frogs.
We have lots of frogs; at least we did and I hope will have again. Apart from times of eco-catastrophe, the tadpoles and frogs here control the mozzie larvae. Frogs also eat mosquitoes. Lots of frogs equals few mozzies. Lots of frogs also equals lots of snakes, who eat the frogs (and the bush rats). I try to remember that each time I have to hop away to avoid a snake.
12 Loss of paper wasps and other predator species
Thirty years ago I washed nappies by hand in two tubs under a giant paper wasp nest. Every day part of the insect haul they had paralysed and brought back to feed their larvae fell into the water where I soaked the nappies: nine days of cabbage butterfly larvae from my crop of cauliflowers, then five days of pear and cherry slug, a few red-back spiders (I hoped they were well and truly paralysed), then other caterpillars I couldn’t recognise.
I took notes over a year of nappy washing. Each time, when I could identify the species, I tracked down their source. The polistes wasps seemed to totally clean up a pest before they moved on to the next – in that location, anyway. That year I was growing over an acre of cauliflowers, but the wasps were enough to do the entire pest control.13
Most market gardeners are not so lucky – or, more likely, they have unknowingly destroyed their native wasps and other predators with pesticides that kill both predator and their food supply. Paper wasp nests can grow to at least twenty square metres, enough to clear up huge numbers of pests. But they are very vulnerable to any pollution from pesticides. One spray of Mortein has been enough to stop them breeding above the sink or the entire window that they tried to colonise one summer.
All pest problems are really lack of predator problems. Locust plagues are a severe ibis deficiency: a mob of ibis can eat two tonnes of grasshoppers a week, and there are native wasps that eat juvenile grasshoppers, too.
When I first came here our orange trees were dying from scale infestation. Three weeks later – after we had saved up enough money to buy spraying equipment and (organic) white oil spray, but had yet to spray it – there were no scale left to spray, but a heck of a lot of ladybird larvae.
And so on
Itemising the many ways our land has been misinterpreted by the vision of colonial farmers could make twelve volumes: feral animals, from camels to cane toads, feral cats, rabbits and goats; myrtle rust devastating remnant bush areas; disruption of aquifers from mining; wild dogs – each deserves at least one chapter on its own (and each is well covered in other books, too). It is easy to see the individual problems, but the overarching effects and root causes are often too broad to be easily grasped.
Our country was once a generous land. In all but the most arid regions it was impossible to walk more than a few steps without passing food. Decades ago – before motherhood, deadlines, email and boxes of mail – I walked this land for much of every day and night. I didn’t carry water, or food. I ate as I walked: berries, leaf tips, oozing sa
p, nectar from blossoms. It didn’t replace dinner and breakfast (though much of that was gathered from the land too) but it was enough to travel on, to keep up energy. Even without the creek there were sources of water, in tree hollows or spring seeps. But this was in land that was relatively untouched by humans. The lower parts of the valley had been grazed, mined, burnt and cleared, but not the steeper land. It remained – and still does as I write this, though I do not know for how much longer – relatively pristine.
When my son first became a weekly high-school boarder he rang me to say, ‘There’s no food here.’
‘Don’t they feed you?’ I asked in horror, remembering Tom Brown’s School Days and other boarding school nightmares.
‘Only in the dining room,’ he said.
Until then I hadn’t realised that he took a generous land for granted, surroundings where there was food always in reach.
We have lost so much. It is impossible to measure the number of species lost, as most had not been identified before they became extinct. (I am roughly extrapolating from the species I know here: at least three appear to be extinct without ever having been formally identified.)
It requires enormous lobbying to even get a species declared as endangered or critically endangered either in the state or federal systems and, even then, few are monitored or so much as given a recovery plan – and when they are, often no one even monitors the recovery plan, much less implements it or prosecutes those who destroy declared species.
Our greatest crime of all, however, was to simplify the bush. For most urban and even rural Australians, ‘the bush’ is tree canopy and ground cover, or shale and tussocks. Repeated burning has created forests where there is almost no understorey, just burrawangs and thin bush, perhaps, where once there were thousands of species.
There may be no such thing as true wilderness in Australia; all our landscape has been modified by humans over millennia. But there is bushland that still has at least a large part of the pre-colonial diversity: pastures with 10,000 ground cover species and over a hundred shrubs and sub-shrubs; grass or terrestrial orchids that have not even been catalogued yet, like the ones I noticed just before Christmas that smell more intensely of roses than any perfume counter but are so high above my head I can’t reach them; lichens; thousands of fungi, again, not even identified; the varied mistletoes; ants that mutate into differing species within three metres.
Let the Land Speak Page 41
